The present invention is directed to a device for use in the manufacture of a product gas containing hydrogen and carbon oxide from a feedgas mixture consisting substantially of hydrocarbon, particularly from natural gas mixed with steam, with the device including a vessel partitioned by a tube sheet into an upper chamber and a lower chamber and reformer tubes secured in the tubesheet and extending downwardly into the lower chamber where each tube is enclosed by a jacket for at least a part of its length.
A device of this kind is known, for example, in DE-OS No. 32 44 252, filed by the applicant. The device includes a a vessel partitioned into two sections by a tubesheet located in the upper third of the vessel, that is, into a more voluminous reaction chamber with reformer tubes and a natural gas/steam chamber in the top section from where the natural gas/steam mixture is distributed to the reformer tubes.
The reformer tubes are jacketed within the reaction chamber. In this chamber, the jackets form a collecting space for discharging the reaction product through an outlet nozzle from the reaction chamber.
In this process the admission of pure oxygen into the reaction chamber and the mixing chamber, respectively, results in an exothermic reaction yielding the product gas. The reaction heat is utilized to heat the reformer tubes with the aid of the tube jackets. A disadvantage inherent in this known design is the exposure of the tubesheet to comparatively high differential pressures between the reaction chamber and the distribution chamber for the feedgas mixture. There is also the disadvantage of the high temperature differences across the tubesheet. The resulting heat loads, stresses, and the like tend to deteriorate the tubesheet. Conversely, the material quality required to satisfy such conditions aggravates the conditions for an economical fabrication of the tubesheet.